Multicore cables

A 16.6 Skin and proximity effects in a multicore cable 16/547 A 16.7 Short-time rating of cables 16/547 A 16.8 Termination of cables 16/548... 

Table A16.19 Rating factors for multicore cables laid on open racks in air...

Table A16.21 Rating factors for groups of twin and multicore cables laid directly in ground in horizontal formation...

The header cable between anode bed and rectifier must be particularly well insulated. For this reason cables with double plastic sheathing of type NYY-O are used. The cable sheath must not be damaged during installation because the copper core at the defects will be anodically attacked in a very short time and the connection to the rectifier broken. Damage to the cable sheath is not so serious if a multicored cable is used. Usually not all the core insulation is damaged so that the operation of the anode bed is not interrupted. In addition, measurement of resistance and detection of defects is easier. 

Animals are placed individually on a stationary treadmill (30 x 10 cm) and are connected to a signal conditioning system (Coulboum Instruments, Allentown, PA 18106, USA, Model V75-01) via a shielded multicore cable, connected at one end to the plug on the animal s head and at the other end to a swivel mounted 30 cm above the center of the treadmill. Animals are then given a 60 minute session with alternating periods of 10 minutes with the treadmill turned on (speed 1.5 rn/rnin) and off. 

In classic intrinsically safe instrumentation multicore cables lead from the control room into the explosion protected system. Several sensors/actuators are wired to a terminal box and connected to the multicore cable. 

Several intrinsically safe circuits may run in a single multicore cable without taking cable faults into account (short-circuits between conductors or conductor break), if ... 

A separate chapter of standard EN 50039 is dedicated to cables in an intrinsically safe system. Special requirements for multicore cables with several intrinsically safe circuits are listed as well as the faults to be assumed between intrinsically safe circuits (wire breaks and short-circuits) if these requirements are not met. In the meantime, these requirements form a part of standards EN 60079-14 and IEC 60079-14 respectively (see Section 6.9.5). 

EC60092-353 Part 353 Single and multicore cables with extruded solid insulation for... 

General instrumentation, control and communication cables. 1EC60092-376 Part 376 Shipboard multicore cables for control circuits. 

BS7629 Part 1 Specification for 300/500 V fire resistance electric cables having low emission of smoke and corrosive gases when affected by fire. Multicore cables (renamed in 1997). Part 2 Specification for 300/500 V fire resistant electric cables having low emission of smoke and corrosive gases when affected by fire. Multipair cables (renamed in 1997). 

Multicore cables having thermoplastic (PVC) or thermosetting insulation, non-armoured COPPER CONDUCTORS Table 4D2A of lET Regulations and Table F5(i) of the On Site Guide Ambient temperature SOX. Conductor operating temperature 70°C Current-carrying capacity (amperes) BS 6004, BS 7629... 

Multicore cables having thermoplastic (PVC) or thermosetting insulation, non-armoured, (COPPER CONDUCTORS) Table 4D1A of lEE Regulations... 

Table A. 2 in lEC 60079-11 for cable parameters may be referred to. Special calculations and considerations are applied for system analysis because of cable faults—especially when multicore cables (see lEC 60079-14 for type A and B cables in connection with multicore cables) are used in the installations [33]. Other important issues here are that (1) voltage drop across the resistor under normal operating conditions has to be taken into account in the design so that there is sufficient voltage at the field device and (2) Zener barriers are properly earthed as shown because without an IS earth they are not safe. To obtain independence from...

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